Front-head construction for self-rotating hammer-drills.



L. C. Bffi. FRONT HEAD CONSTRUCTION Fou p51. wTA'I'ING HAMMER DBILLS. APPLICATION FILED 1255.5, w51, xrNLwED JAN. 4, 1915.

1,180 957, Patented Mar.9,1915.

BY l Wag-@ A TTOHNEY UNITED s'raTns PATENT OFFICE.

LEWIS C. BAYLES, OF EASTQN, PENNSYLVANIA, ASSIGNOR T9 INGERSOLL-RAND COMPANY, OF JERSEY CITY, NEVI JERSEY, A CORPORATION 0F NEXV JERSEY.

FRONT-HEAD CONSTRUCTION FOR. SELF-ROTATING HAMMERTDRILLS.

Specification of Letters Patent.

Patented Mai. 9, 1915.

Application filed February 5, 1914, Serial No. 816,814. Renewed January 4, 1'915. Serial No. 509.

To all whom it may concern Be it known that I, LEWIS C. Baynes, a citizen of the United States, residing at Easton, in the county of Northampton and State of Pennsylvania, have invented a cer tain new and useful Improvement in F ront- Head Construction for Self-Rotating Harnmer-Drills, of which the following is a specification.

This invention relates to self-rotating hammer drills and more particularly to ay front head construction for drills of this type for use in stoping or other drilling Where it is necessary to drill vertical holes in the roof of a stope or entry.

The object of this invention is to provide a front head construction for drills of this type which will' prevent dust from the hole from penetrating into the Working parts the drill'when it is used in vertical or ne vertical drilling. With this object in a fronthead construction has been devised, a practical embodiment of which is shown in the accompanying drawings in ivhich- Figure 1 shows a longitudinal section of drill partly in elevation and F ig. 2 shows a transverse section taken on the line 2 2 of Fig. l.

In the drawings, the invention is shown applied to a stoping drill provided With an air feed of-ordinary construction, the details of Which form no partv of the-present invention. l

'As shown, the drill comprises a head block 1 to one side of Which is secured an air feed 2 and to the other side of which is secured a drill cylinder 3 in which reciproc'a'tes a piston 4. the movement of Which is governed by any desired form of valve mechanism (not shown). The piston is given a step lby step rotation by means of a fluted rifle bar 5 provided 'with the ordinary ratchet mechanism G, this rifle bar 5 Asliding in a. bore '7 in the head of the piston provid d with grooves which are engaged by the utes on the rilie bar 5. On the forward sidev of the piston isa hammer liar extension 8 which is provided With straight flutes 9. Fitting'into the forward end of the cylinder 3 is a cylinder head 10. In' the rear- Ward side ofthe cylinder head 10 is a bore 11 through which the hammer bar extension 8 projects. Fora :1rd of this Yis a larger bore 12 and forward of this second bore is a third bore 13 of still l; f diameter. Forthe tappet 25.

Ward o f the cylinder head 10 is a front head il which is secured by bolts 15 passing through lugs 16 to the cylinder 3 which is also provided with lugsl 17 through which the bolts 15 pass. Springs 18 are provided between the heads of the bolts 15 and the 1G to cushion the blow of the pist-on 4 on the cylinder head when the drill is not against theivork.' i The front head 14 has an interior bore of the same diameter as the second bore 12 of the cylinder head. Rota# tably mounted in the front headl 14 is a shank portion il) of a drill chuck 20. The rear end of this shank portion extends back and tits into the bore 12 and has an annular depression 21 in its outer surface which registers with the bore 13. In the annular chamber formed by this depression 21 and the. bore 13 split retaining i "i A engages the ar edge of the fr and prevents u ingitudinal movement oi drill chuck 20. These parts asse in the following manner: The shank p l) is slid into position within the front head 'la and the split ring 22 placed in the depression ZL These parts are'then slid intoL place inI the cylinder head 10 and secured together by means of the bolts 15. The shank portion 19 of the drill chuck is bored out to receive the hammer bar extension of the piston and isprovided on its'inner sur face with grooves engaging the straight flutes 9 of the hammer bar extension. The drill chueklQO is provided with a head portion 23 of larger diameter, the rear' face of which overlaps the front end of the front head 1-l and prevents any dust falling on the front end of the drill from entering the drill cylinder at the joint between these parts. The head portion of the chuck is bored out from its front end to receive the head portion 24 of a tappet 25 the shank 26 of which projects through a smaller bore into the interior of the shank portion 19 of the chuck so that it is struck by the hammer bar extension 8 of the piston 4. Threaded into the forward end of the head portion 23 of the chuck is a nose piece 27 through which is an angular longitudinal aperture 28 for the reception of the drill steel (not shown) the rear end of which can thus be struck by The thread of the nose piece 2T is arranged in the `same direction as the spiral utes on the rifle bar 5 so that the rotation of the piston tends to tighten the nose 30 gmunicated to lthe chuck by piece in the head portion of the chuck. Rearwardly inclined passages 29 are provided through the head portion of the chuck from the tappet bore so that any dust pene- 5 trating into the bore along the shank of the drill steel can easily escape and not work' into the cylinder.

he operation ofthe device can easily .be seen from the ,drawings and description. The rotary movement of the piston caused by the rifie bar 5 will be communicated to the drill chuck by means of the straight tintes 9 on the hammer bar extension of the piston causing relative rotation between the head portion 23 and the front head 14. With drills of ordinary dust falling from the hole works down into the moving parts of the drill quickly resulting in destructive wear of the drill. In the present form the joint between the chuck andfront-head is entirely covered by the overlapping rear end the chuck and by this means and also by the rearwardly inclined passages rom the tappet bore, dust is entirely ifrevented from entering this cylinder and a ecting the moving parts.

Although the chuck is here shown rotated by the rotary movement of the piston comthe fluted forward extension of the piston, it is obvious that other means might be employed without invention for directly or indirectly rotating the chuck and it is to be understood that the present showing and description discloses only one specified modification of my invention and other forms and modifications are included in the spirit and scope of the in vention as expressed in the claims.

What I claim is:

1. In a fluid operated percussive drill, a cylinder, a front head secured to said cylinder, a drill steel receiving chuck having a shank portion rotatably'mounted in said front head and a head portion of larger diameter overlapping the front end of said front head and havin an angular steel receiving aperture therein, a split ring engaging said chuck shank and the rear end of said front head to prevent forward movement of said chuck and means for rotating said chuck.

2. In avfluid operated percussive drill, a cylinder, a self rotating piston having a forward extension, a front head secured to said cylinder, a drill receiving chuck having a rearward portion rotating in said front head and slidably engaged by said piston extension, said chuck having a head portionlof larger diameter overlapping the forward edge of said front head and having an angulardrill receiving aperture, and a split ring engaging said chuck and the rear edge of said front head to prevent forward move- B6 ment of said chuck.

construction the of the h'ead portion of l the front end of said 3. In' a fluid operated percussive drill, a

cylinder, a front head therefor, a drill chuck rotatably mounted in said front head, said drill chuck having an enlarged head portion overlapping the frontedge of said front head and a ring secured to its rear end engaging the rear edge of said front head'to cylinder, a front head therefor, a drill chuck rotatably mounted in said front' head, said drill chuck having an enlarged head portion overlapping the front edge of said front head and a ring secured to its rear end engaging the rear edge of said front head to prevent longitudinal movement, means to secure said front head to said cylinder anda piston having a' luted extension` engaging said drill chuck.

5. In a Huid operated percussive drill, a cylinder, a front head secured thereto, a drill chuck having a shank portion rotatably mounted in said front head and a head portion overlapping the end of said front head, said head portion having a tappet receiving bore in its front end, a tappet in said bore having a shank projecting intoisaid chuck shank portion, a nose piece secured ini'said bore to retain said tappet in position, said nose piece having an angular aperture therethrough for the reception of a drill steel, and a piston having a forward extension sliding in said said tappet.

6. In a duid operated percussive drill, a cylinder, a piston therein having a forward extension, a cylinder head for said cylinder having a bore for the passage of said forward extension, a larger bore forward of said first bore and a third, bore of greater diameter forward of said second bore, a front head to engage the rear edge of said front head,A

a head portion on said chuck overlapping front head and means for rotating said chuck.

In a Huid operated percussive drill, a cylinder, a piston therein having a tinted forward extension, means for rotatin said piston, a cylinder, head for said Ycy ind'er having a bore for the passage of said forward extension, la larger bore forward of said first bore anda third bore of greater diameter `forward of said second bore, a

chuck and adapted to strike v forward of said cylinder head l A having a bore of the same 'diameter as said front head forward of said cylinder head having a bore of the same diameter as said second cylinder head bore, a drill chuck having a shank portion fitting said front head bore and said second cylinder head bore and engaged by said piston extension, said shank portion having a depression registering with said third cylinder head bore, a split ring Seated in said depressionand projecting into 10 said third bore to engage the rear edge of said front head, and a head portion on said chuck overlapping the front end of said front head.

In testimony whereof, I have hereunto set my hand.

LEWIS C. BAYLES.

IVitnesses:

CLARENCE MAHN, C. S. MILEY. 

